One credit-card stored in one place
If I have an app store, I have one means of payment. I can register my credit card (whatever type - I don't need to worry if you take Amex/Visa/MCard/Whatever and what country it's registered in, or what currency) in one place and know who the merchant is.
I don't have lots of different web-sites storing my card details. Or if I don't want you to store them (and I don't) then I don't have to type my details over and over again if I want to buy your software.
I can actually recognise the merchant name - I don't have to worry about 'xyz s/w holdings, Bermuda' and whether that's really the software/upgrade I bought or a scammer.
And neither does my card issuer, so my card doesn't get fraud-blocked when I need to spend 0.99 on an in-app purchase and it flags as suspicious.
And there's no 'minimum card value 10.00' restriction: In fact app-stores bundle-up purchases if you buy a lot of things on the same day.
Alternatively, I can buy vouchers for most app stores with cash and not have to worry about credit cards at all.
One user ID & password and one source of spam
I want to use your software or app. I'm happy to pay you for it - you put in the hard work so you should get my cash and that's all good.
What I don't want is to have to 'register an account' with you and have to remember yet another password.
I also don't want mail from you or 'selected partners'.
No, really I don't.
If I've bought games (or anything else) I like then I'll sign up to your mailing list for updates and 'social' stuff, I'll follow you on Twitter or Facebook, but if I've just bought a hex editor or a GPS app then just take the money already.
I don't want 'a relationship'. If there's a new version, flag it in the store and I'll pick it up. The store's notify system will sort it all out for you.
One place to get all the updates
This is what prompted this post: One place that says 'nn updates available' so that I can click 'update all' and let it get on with it.
I have phones and laptops I don't turn on all that often. When I do, I just want to click a button marked 'update everything on my computer' and let it get on with it.
Without any more hassle.
Preferably in the background.
Without me having to open every single app and click 'check for updates'.
Without me having to update your 'updater' program before I can check for updates.
And only having to type in my 'admin' password once, not once per app.
And really, really preferably, without having to reboot.
On a positive note:
Having run 6 separate updates, at least only one (an update to MacOS itself) has asked me to restart my computer. On Windows that request used to happen every time I updated anything - was it ever really necessary or did people do it 'just in case'?